UPCAT Science Ultimate Exam
**Question 1.** Which organelle is primarily responsible for ATP production in eukaryotic cells?
A) Nucleus
B) Golgi apparatus
C) Mitochondrion
D) Lysosome
Answer: C
Explanation: Mitochondria generate ATP through oxidative phosphorylation, the main energy-producing
process in eukaryotes.
**Question 2.** In a prokaryotic cell, genetic material is located in the:
A) Nucleus
B) Nucleoid region
C) Mitochondrion
D) Chloroplast
Answer: B
Explanation: Prokaryotes lack a true nucleus; their circular DNA resides in a nucleoid region.
**Question 3.** Which of the following best describes facilitated diffusion?
A) Movement of solutes against a concentration gradient using ATP
B) Passive movement through a protein channel down a concentration gradient
C) Active transport of ions via pumps
D) Osmosis of water through a semi-permeable membrane
Answer: B
Explanation: Facilitated diffusion uses carrier or channel proteins to allow specific molecules to move
down their gradient without energy input.
**Question 4.** The primary structural component of plant cell walls is:
A) Cellulose
B) Chitin
, UPCAT Science Ultimate Exam
C) Glycogen
D) Collagen
Answer: A
Explanation: Cellulose is a polysaccharide that forms strong microfibrils providing rigidity to plant cell
walls.
**Question 5.** Which of the following is a monomer of proteins?
A) Glucose
B) Fatty acid
C) Amino acid
D Nucleotide
Answer: C
Explanation: Proteins are polymers of amino acids linked by peptide bonds.
**Question 6.** During which phase of mitosis do sister chromatids separate and move toward
opposite poles?
A) Prophase
B) Metaphase
C) Anaphase
D) Telophase
Answer: C
Explanation: In anaphase, the spindle fibers pull sister chromatids apart to opposite cell poles.
**Question 7.** In cellular respiration, the net production of ATP from one molecule of glucose under
aerobic conditions is approximately:
A) 2 ATP
B) 4 ATP
C) 30-32 ATP
D) 100 ATP
Answer: C
, UPCAT Science Ultimate Exam
Explanation: Glycolysis, the citric acid cycle, and oxidative phosphorylation together yield about 30-32
ATP per glucose.
**Question 8.** Which pigment absorbs light most efficiently at 680 nm in photosystem II?
A) Chlorophyll a
B) Chlorophyll b
C) Carotene
D) Phycocyanin
Answer: A
Explanation: Chlorophyll a has a peak absorption near 680 nm, the reaction center pigment of
photosystem II.
**Question 9.** In a monohybrid cross where the dominant allele is represented by “A”, what is the
phenotypic ratio of the F₂ generation?
A) 1:1
B) 3:1
C) 9:3:3:1
D) 2:1
Answer: B
Explanation: A classic Mendelian monohybrid cross (Aa × Aa) yields a 3 dominant : 1 recessive
phenotypic ratio.
**Question 10.** Codominance is best illustrated by which human blood type inheritance pattern?
A) A and B alleles produce type AB blood
B) A allele masks O allele
C) O allele is recessive to A and B
D) A allele is partially expressed over O
Answer: A
Explanation: Both A and B alleles are expressed equally on the surface of red cells, giving the AB
phenotype.
, UPCAT Science Ultimate Exam
**Question 11.** The enzyme responsible for unwinding DNA during replication is:
A) DNA polymerase I
B) DNA helicase
C) RNA polymerase
D) Ligase
Answer: B
Explanation: DNA helicase breaks hydrogen bonds between base pairs, separating the strands for
replication.
**Question 12.** According to the central dogma, the correct order of information flow is:
A) DNA → RNA → Protein
B) Protein → RNA → DNA
C) RNA → DNA → Protein
D) DNA → Protein → RNA
Answer: A
Explanation: Genetic information is transcribed from DNA to RNA and then translated into protein.
**Question 13.** A point mutation that changes a codon from AAA to AAG results in:
A) A nonsense mutation
B) A frameshift mutation
C) A silent mutation
D) A missense mutation
Answer: C
Explanation: Both AAA and AAG code for lysine; the amino acid sequence remains unchanged.
**Question 14.** Which of the following is NOT a function of the human skeletal system?
A) Protection of internal organs
B) Production of red blood cells
**Question 1.** Which organelle is primarily responsible for ATP production in eukaryotic cells?
A) Nucleus
B) Golgi apparatus
C) Mitochondrion
D) Lysosome
Answer: C
Explanation: Mitochondria generate ATP through oxidative phosphorylation, the main energy-producing
process in eukaryotes.
**Question 2.** In a prokaryotic cell, genetic material is located in the:
A) Nucleus
B) Nucleoid region
C) Mitochondrion
D) Chloroplast
Answer: B
Explanation: Prokaryotes lack a true nucleus; their circular DNA resides in a nucleoid region.
**Question 3.** Which of the following best describes facilitated diffusion?
A) Movement of solutes against a concentration gradient using ATP
B) Passive movement through a protein channel down a concentration gradient
C) Active transport of ions via pumps
D) Osmosis of water through a semi-permeable membrane
Answer: B
Explanation: Facilitated diffusion uses carrier or channel proteins to allow specific molecules to move
down their gradient without energy input.
**Question 4.** The primary structural component of plant cell walls is:
A) Cellulose
B) Chitin
, UPCAT Science Ultimate Exam
C) Glycogen
D) Collagen
Answer: A
Explanation: Cellulose is a polysaccharide that forms strong microfibrils providing rigidity to plant cell
walls.
**Question 5.** Which of the following is a monomer of proteins?
A) Glucose
B) Fatty acid
C) Amino acid
D Nucleotide
Answer: C
Explanation: Proteins are polymers of amino acids linked by peptide bonds.
**Question 6.** During which phase of mitosis do sister chromatids separate and move toward
opposite poles?
A) Prophase
B) Metaphase
C) Anaphase
D) Telophase
Answer: C
Explanation: In anaphase, the spindle fibers pull sister chromatids apart to opposite cell poles.
**Question 7.** In cellular respiration, the net production of ATP from one molecule of glucose under
aerobic conditions is approximately:
A) 2 ATP
B) 4 ATP
C) 30-32 ATP
D) 100 ATP
Answer: C
, UPCAT Science Ultimate Exam
Explanation: Glycolysis, the citric acid cycle, and oxidative phosphorylation together yield about 30-32
ATP per glucose.
**Question 8.** Which pigment absorbs light most efficiently at 680 nm in photosystem II?
A) Chlorophyll a
B) Chlorophyll b
C) Carotene
D) Phycocyanin
Answer: A
Explanation: Chlorophyll a has a peak absorption near 680 nm, the reaction center pigment of
photosystem II.
**Question 9.** In a monohybrid cross where the dominant allele is represented by “A”, what is the
phenotypic ratio of the F₂ generation?
A) 1:1
B) 3:1
C) 9:3:3:1
D) 2:1
Answer: B
Explanation: A classic Mendelian monohybrid cross (Aa × Aa) yields a 3 dominant : 1 recessive
phenotypic ratio.
**Question 10.** Codominance is best illustrated by which human blood type inheritance pattern?
A) A and B alleles produce type AB blood
B) A allele masks O allele
C) O allele is recessive to A and B
D) A allele is partially expressed over O
Answer: A
Explanation: Both A and B alleles are expressed equally on the surface of red cells, giving the AB
phenotype.
, UPCAT Science Ultimate Exam
**Question 11.** The enzyme responsible for unwinding DNA during replication is:
A) DNA polymerase I
B) DNA helicase
C) RNA polymerase
D) Ligase
Answer: B
Explanation: DNA helicase breaks hydrogen bonds between base pairs, separating the strands for
replication.
**Question 12.** According to the central dogma, the correct order of information flow is:
A) DNA → RNA → Protein
B) Protein → RNA → DNA
C) RNA → DNA → Protein
D) DNA → Protein → RNA
Answer: A
Explanation: Genetic information is transcribed from DNA to RNA and then translated into protein.
**Question 13.** A point mutation that changes a codon from AAA to AAG results in:
A) A nonsense mutation
B) A frameshift mutation
C) A silent mutation
D) A missense mutation
Answer: C
Explanation: Both AAA and AAG code for lysine; the amino acid sequence remains unchanged.
**Question 14.** Which of the following is NOT a function of the human skeletal system?
A) Protection of internal organs
B) Production of red blood cells
